Webcams offer a low-cost way to tune lasers for serious science

Dec 04, 2012

Every photon in a laser beam marches in lockstep, at an identical wavelength that depends on what the laser is used for – for example, infrared lasers that drive the optic fiber internet. For many applications, lasers need to be precisely tuned to those wavelengths, and the wavelength-measuring instruments can be more expensive than the lasers themselves.

Now, using a handful of inexpensive components – including an off-the-shelf computer webcam and a small diffraction grating, a device for splitting and diffracting light into several beams – researchers have built a diffraction spectrometer that can tune lasers with better than one part-per-million accuracy.

"The accessibility, simplicity, and cost make it feasible to provide such precision measurements for every single laser in a laboratory," says physicist and study co-author Robert E. Scholten of the University of Melbourne.

Indeed, Scholten says, the instrument, which is described in the AIP's journal Review of Scientific Advances, is simple enough to be constructed in undergraduate physics labs – "and could easily be a high-school project," he adds. "It would provide excellent training in optics and the wave nature of light, and once constructed, the device can be used to elucidate the quantum mechanical structure of matter, for example by measuring the fine-structure splitting or even the hyperfine structure of atoms such as sodium."

More information: "Compact diffraction grating laser wavemeter with sub-picometer accuracy and picowatt sensitivity using a webcam imaging sensor" is published in Review of Scientific Instruments. rsi.aip.org/resource/1/rsinak/v83/i11/p113104_s1

Related Stories

(PhysOrg.com) -- Silicon is an ideal platform for integrated photonic circuits because the material is cheap and readily available. Silicon chips with an integrated laser source capable of emitting light at ...

(PhysOrg.com) -- One of the drawbacks associated with using semiconductor lasers is that many of them can only produce a beam of a single wavelength, and can only send that beam in one direction at a time. ...

A tiny device for calibrating or stabilizing precision lasers has been designed and demonstrated at the National Institute of Standards and Technology. The prototype device could replace table-top-sized instruments ...

Transmitting information as pulses of light through fiber-optic cables is the fastest and highest-bandwidth communications technology that exists today. Yet even this technology is being pressed to carry ever-greater ...

To look at small objects typically requires big machines. For example, the study of single atoms with a laser requires x-ray radiation of such high energy that it is only produced by accelerating electrons ...

Recommended for you

Dielectric elastomers are novel materials for making actuators or motors with soft and lightweight properties that can undergo large active deformations with high-energy conversion efficiencies. This has ...

Plants living in arid, mountainous and humid regions of the planet often rely on their leaves to obtain the moisture they need for survival by pulling mist out of the air. But how exactly they manage this ...

There are electrical signals in the nervous system, the brain and throughout the human body and there are tiny magnetic fields associated with these signals that could be important for medical science. Researchers ...

(Phys.org)—A pair of Turkish space scientists with Bogazici University has proposed that researchers looking for the existence of Dyson spheres might be looking at the wrong objects. İbrahim Semiz and ...

So secretive were efforts to create the first self-sustained nuclear reaction in 1942 that physicist Enrico Fermi and his Manhattan Project team quietly toiled beneath the stands of Stagg Field and communicated ...